First evidence of West Nile virus reported this year in Lake County

The region’s first confirmed evidence of West Nile virus this season has turned up in a bird found dead June 23 in the city of Clearlake, Lake County officials announced Saturday.

Positive test results for the black-headed grosbeak make Lake County the latest of 17 California counties to report the virus’ presence so far this year, though the season is far from reaching its peak.

“This tells us that WNV is being transmitted by mosquitoes right now, and we expect that activity will continue for the rest of the summer,” Lake County Vector Control District Manager Jamesina Scott said in a written statement.

The disease, first detected in North America in 1999, has spread through mosquitoes that feed on infected birds and then bite humans and other animals, infecting them.

Most people experience no symptoms, but about one in five will develop fever and other flu like symptoms including body aches, joint pain, vomiting, diarrhea and rash. A small number, less than 1 percent, may develop serious neurological problems, including possible death.

More than 400 mosquito samples and 39 birds positive for West Nile virus have been found in California this year, with most activity in the southern and central parts of the state.

Three human cases have been reported, including one new case this week in Kern County. No signs of the virus have been reported in 2017 in Sonoma, Marin, Mendocino and Napa counties.